

/**

 * Copyright (c) 2014-present, Facebook, Inc.

 *

 * This source code is licensed under the MIT license found in the

 * LICENSE file in the root directory of this source tree.

 */



var regeneratorRuntime = (function (exports) {

  "use strict";



  var Op = Object.prototype;

  var hasOwn = Op.hasOwnProperty;

  var undefined; // More compressible than void 0.

  var $Symbol = typeof Symbol === "function" ? Symbol : {};

  var iteratorSymbol = $Symbol.iterator || "@@iterator";

  var asyncIteratorSymbol = $Symbol.asyncIterator || "@@asyncIterator";

  var toStringTagSymbol = $Symbol.toStringTag || "@@toStringTag";



  function wrap(innerFn, outerFn, self, tryLocsList) {

    // If outerFn provided and outerFn.prototype is a Generator, then outerFn.prototype instanceof Generator.

    var protoGenerator = outerFn && outerFn.prototype instanceof Generator ? outerFn : Generator;

    var generator = Object.create(protoGenerator.prototype);

    var context = new Context(tryLocsList || []);



    // The ._invoke method unifies the implementations of the .next,

    // .throw, and .return methods.

    generator._invoke = makeInvokeMethod(innerFn, self, context);



    return generator;

  }

  exports.wrap = wrap;



  // Try/catch helper to minimize deoptimizations. Returns a completion

  // record like context.tryEntries[i].completion. This interface could

  // have been (and was previously) designed to take a closure to be

  // invoked without arguments, but in all the cases we care about we

  // already have an existing method we want to call, so there's no need

  // to create a new function object. We can even get away with assuming

  // the method takes exactly one argument, since that happens to be true

  // in every case, so we don't have to touch the arguments object. The

  // only additional allocation required is the completion record, which

  // has a stable shape and so hopefully should be cheap to allocate.

  function tryCatch(fn, obj, arg) {

    try {

      return { type: "normal", arg: fn.call(obj, arg) };

    } catch (err) {

      return { type: "throw", arg: err };

    }

  }



  var GenStateSuspendedStart = "suspendedStart";

  var GenStateSuspendedYield = "suspendedYield";

  var GenStateExecuting = "executing";

  var GenStateCompleted = "completed";



  // Returning this object from the innerFn has the same effect as

  // breaking out of the dispatch switch statement.

  var ContinueSentinel = {};



  // Dummy constructor functions that we use as the .constructor and

  // .constructor.prototype properties for functions that return Generator

  // objects. For full spec compliance, you may wish to configure your

  // minifier not to mangle the names of these two functions.

  function Generator() {}

  function GeneratorFunction() {}

  function GeneratorFunctionPrototype() {}



  // This is a polyfill for %IteratorPrototype% for environments that

  // don't natively support it.

  var IteratorPrototype = {};

  IteratorPrototype[iteratorSymbol] = function () {

    return this;

  };



  var getProto = Object.getPrototypeOf;

  var NativeIteratorPrototype = getProto && getProto(getProto(values([])));

  if (NativeIteratorPrototype &&

      NativeIteratorPrototype !== Op &&

      hasOwn.call(NativeIteratorPrototype, iteratorSymbol)) {

    // This environment has a native %IteratorPrototype%; use it instead

    // of the polyfill.

    IteratorPrototype = NativeIteratorPrototype;

  }



  var Gp = GeneratorFunctionPrototype.prototype =

    Generator.prototype = Object.create(IteratorPrototype);

  GeneratorFunction.prototype = Gp.constructor = GeneratorFunctionPrototype;

  GeneratorFunctionPrototype.constructor = GeneratorFunction;

  GeneratorFunctionPrototype[toStringTagSymbol] =

    GeneratorFunction.displayName = "GeneratorFunction";



  // Helper for defining the .next, .throw, and .return methods of the

  // Iterator interface in terms of a single ._invoke method.

  function defineIteratorMethods(prototype) {

    ["next", "throw", "return"].forEach(function(method) {

      prototype[method] = function(arg) {

        return this._invoke(method, arg);

      };

    });

  }



  exports.isGeneratorFunction = function(genFun) {

    var ctor = typeof genFun === "function" && genFun.constructor;

    return ctor

      ? ctor === GeneratorFunction ||

        // For the native GeneratorFunction constructor, the best we can

        // do is to check its .name property.

        (ctor.displayName || ctor.name) === "GeneratorFunction"

      : false;

  };



  exports.mark = function(genFun) {

    if (Object.setPrototypeOf) {

      Object.setPrototypeOf(genFun, GeneratorFunctionPrototype);

    } else {

      genFun.__proto__ = GeneratorFunctionPrototype;

      if (!(toStringTagSymbol in genFun)) {

        genFun[toStringTagSymbol] = "GeneratorFunction";

      }

    }

    genFun.prototype = Object.create(Gp);

    return genFun;

  };



  // Within the body of any async function, `await x` is transformed to

  // `yield regeneratorRuntime.awrap(x)`, so that the runtime can test

  // `hasOwn.call(value, "__await")` to determine if the yielded value is

  // meant to be awaited.

  exports.awrap = function(arg) {

    return { __await: arg };

  };



  function AsyncIterator(generator) {

    function invoke(method, arg, resolve, reject) {

      var record = tryCatch(generator[method], generator, arg);

      if (record.type === "throw") {

        reject(record.arg);

      } else {

        var result = record.arg;

        var value = result.value;

        if (value &&

            typeof value === "object" &&

            hasOwn.call(value, "__await")) {

          return Promise.resolve(value.__await).then(function(value) {

            invoke("next", value, resolve, reject);

          }, function(err) {

            invoke("throw", err, resolve, reject);

          });

        }



        return Promise.resolve(value).then(function(unwrapped) {

          // When a yielded Promise is resolved, its final value becomes

          // the .value of the Promise<{value,done}> result for the

          // current iteration.

          result.value = unwrapped;

          resolve(result);

        }, function(error) {

          // If a rejected Promise was yielded, throw the rejection back

          // into the async generator function so it can be handled there.

          return invoke("throw", error, resolve, reject);

        });

      }

    }



    var previousPromise;



    function enqueue(method, arg) {

      function callInvokeWithMethodAndArg() {

        return new Promise(function(resolve, reject) {

          invoke(method, arg, resolve, reject);

        });

      }



      return previousPromise =

        // If enqueue has been called before, then we want to wait until

        // all previous Promises have been resolved before calling invoke,

        // so that results are always delivered in the correct order. If

        // enqueue has not been called before, then it is important to

        // call invoke immediately, without waiting on a callback to fire,

        // so that the async generator function has the opportunity to do

        // any necessary setup in a predictable way. This predictability

        // is why the Promise constructor synchronously invokes its

        // executor callback, and why async functions synchronously

        // execute code before the first await. Since we implement simple

        // async functions in terms of async generators, it is especially

        // important to get this right, even though it requires care.

        previousPromise ? previousPromise.then(

          callInvokeWithMethodAndArg,

          // Avoid propagating failures to Promises returned by later

          // invocations of the iterator.

          callInvokeWithMethodAndArg

        ) : callInvokeWithMethodAndArg();

    }



    // Define the unified helper method that is used to implement .next,

    // .throw, and .return (see defineIteratorMethods).

    this._invoke = enqueue;

  }



  defineIteratorMethods(AsyncIterator.prototype);

  AsyncIterator.prototype[asyncIteratorSymbol] = function () {

    return this;

  };

  exports.AsyncIterator = AsyncIterator;



  // Note that simple async functions are implemented on top of

  // AsyncIterator objects; they just return a Promise for the value of

  // the final result produced by the iterator.

  exports.async = function(innerFn, outerFn, self, tryLocsList) {

    var iter = new AsyncIterator(

      wrap(innerFn, outerFn, self, tryLocsList)

    );



    return exports.isGeneratorFunction(outerFn)

      ? iter // If outerFn is a generator, return the full iterator.

      : iter.next().then(function(result) {

          return result.done ? result.value : iter.next();

        });

  };



  function makeInvokeMethod(innerFn, self, context) {

    var state = GenStateSuspendedStart;



    return function invoke(method, arg) {

      if (state === GenStateExecuting) {

        throw new Error("Generator is already running");

      }



      if (state === GenStateCompleted) {

        if (method === "throw") {

          throw arg;

        }



        // Be forgiving, per 25.3.3.3.3 of the spec:

        // https://people.mozilla.org/~jorendorff/es6-draft.html#sec-generatorresume

        return doneResult();

      }



      context.method = method;

      context.arg = arg;



      while (true) {

        var delegate = context.delegate;

        if (delegate) {

          var delegateResult = maybeInvokeDelegate(delegate, context);

          if (delegateResult) {

            if (delegateResult === ContinueSentinel) continue;

            return delegateResult;

          }

        }



        if (context.method === "next") {

          // Setting context._sent for legacy support of Babel's

          // function.sent implementation.

          context.sent = context._sent = context.arg;



        } else if (context.method === "throw") {

          if (state === GenStateSuspendedStart) {

            state = GenStateCompleted;

            throw context.arg;

          }



          context.dispatchException(context.arg);



        } else if (context.method === "return") {

          context.abrupt("return", context.arg);

        }



        state = GenStateExecuting;



        var record = tryCatch(innerFn, self, context);

        if (record.type === "normal") {

          // If an exception is thrown from innerFn, we leave state ===

          // GenStateExecuting and loop back for another invocation.

          state = context.done

            ? GenStateCompleted

            : GenStateSuspendedYield;



          if (record.arg === ContinueSentinel) {

            continue;

          }



          return {

            value: record.arg,

            done: context.done

          };



        } else if (record.type === "throw") {

          state = GenStateCompleted;

          // Dispatch the exception by looping back around to the

          // context.dispatchException(context.arg) call above.

          context.method = "throw";

          context.arg = record.arg;

        }

      }

    };

  }



  // Call delegate.iterator[context.method](context.arg) and handle the

  // result, either by returning a { value, done } result from the

  // delegate iterator, or by modifying context.method and context.arg,

  // setting context.delegate to null, and returning the ContinueSentinel.

  function maybeInvokeDelegate(delegate, context) {

    var method = delegate.iterator[context.method];

    if (method === undefined) {

      // A .throw or .return when the delegate iterator has no .throw

      // method always terminates the yield* loop.

      context.delegate = null;



      if (context.method === "throw") {

        if (delegate.iterator.return) {

          // If the delegate iterator has a return method, give it a

          // chance to clean up.

          context.method = "return";

          context.arg = undefined;

          maybeInvokeDelegate(delegate, context);



          if (context.method === "throw") {

            // If maybeInvokeDelegate(context) changed context.method from

            // "return" to "throw", let that override the TypeError below.

            return ContinueSentinel;

          }

        }



        context.method = "throw";

        context.arg = new TypeError(

          "The iterator does not provide a 'throw' method");

      }



      return ContinueSentinel;

    }



    var record = tryCatch(method, delegate.iterator, context.arg);



    if (record.type === "throw") {

      context.method = "throw";

      context.arg = record.arg;

      context.delegate = null;

      return ContinueSentinel;

    }



    var info = record.arg;



    if (! info) {

      context.method = "throw";

      context.arg = new TypeError("iterator result is not an object");

      context.delegate = null;

      return ContinueSentinel;

    }



    if (info.done) {

      // Assign the result of the finished delegate to the temporary

      // variable specified by delegate.resultName (see delegateYield).

      context[delegate.resultName] = info.value;



      // Resume execution at the desired location (see delegateYield).

      context.next = delegate.nextLoc;



      // If context.method was "throw" but the delegate handled the

      // exception, let the outer generator proceed normally. If

      // context.method was "next", forget context.arg since it has been

      // "consumed" by the delegate iterator. If context.method was

      // "return", allow the original .return call to continue in the

      // outer generator.

      if (context.method !== "return") {

        context.method = "next";

        context.arg = undefined;

      }



    } else {

      // Re-yield the result returned by the delegate method.

      return info;

    }



    // The delegate iterator is finished, so forget it and continue with

    // the outer generator.

    context.delegate = null;

    return ContinueSentinel;

  }



  // Define Generator.prototype.{next,throw,return} in terms of the

  // unified ._invoke helper method.

  defineIteratorMethods(Gp);



  Gp[toStringTagSymbol] = "Generator";



  // A Generator should always return itself as the iterator object when the

  // @@iterator function is called on it. Some browsers' implementations of the

  // iterator prototype chain incorrectly implement this, causing the Generator

  // object to not be returned from this call. This ensures that doesn't happen.

  // See https://github.com/facebook/regenerator/issues/274 for more details.

  Gp[iteratorSymbol] = function() {

    return this;

  };



  Gp.toString = function() {

    return "[object Generator]";

  };



  function pushTryEntry(locs) {

    var entry = { tryLoc: locs[0] };



    if (1 in locs) {

      entry.catchLoc = locs[1];

    }



    if (2 in locs) {

      entry.finallyLoc = locs[2];

      entry.afterLoc = locs[3];

    }



    this.tryEntries.push(entry);

  }



  function resetTryEntry(entry) {

    var record = entry.completion || {};

    record.type = "normal";

    delete record.arg;

    entry.completion = record;

  }



  function Context(tryLocsList) {

    // The root entry object (effectively a try statement without a catch

    // or a finally block) gives us a place to store values thrown from

    // locations where there is no enclosing try statement.

    this.tryEntries = [{ tryLoc: "root" }];

    tryLocsList.forEach(pushTryEntry, this);

    this.reset(true);

  }



  exports.keys = function(object) {

    var keys = [];

    for (var key in object) {

      keys.push(key);

    }

    keys.reverse();



    // Rather than returning an object with a next method, we keep

    // things simple and return the next function itself.

    return function next() {

      while (keys.length) {

        var key = keys.pop();

        if (key in object) {

          next.value = key;

          next.done = false;

          return next;

        }

      }



      // To avoid creating an additional object, we just hang the .value

      // and .done properties off the next function object itself. This

      // also ensures that the minifier will not anonymize the function.

      next.done = true;

      return next;

    };

  };



  function values(iterable) {

    if (iterable) {

      var iteratorMethod = iterable[iteratorSymbol];

      if (iteratorMethod) {

        return iteratorMethod.call(iterable);

      }



      if (typeof iterable.next === "function") {

        return iterable;

      }



      if (!isNaN(iterable.length)) {

        var i = -1, next = function next() {

          while (++i < iterable.length) {

            if (hasOwn.call(iterable, i)) {

              next.value = iterable[i];

              next.done = false;

              return next;

            }

          }



          next.value = undefined;

          next.done = true;



          return next;

        };



        return next.next = next;

      }

    }



    // Return an iterator with no values.

    return { next: doneResult };

  }

  exports.values = values;



  function doneResult() {

    return { value: undefined, done: true };

  }



  Context.prototype = {

    constructor: Context,



    reset: function(skipTempReset) {

      this.prev = 0;

      this.next = 0;

      // Resetting context._sent for legacy support of Babel's

      // function.sent implementation.

      this.sent = this._sent = undefined;

      this.done = false;

      this.delegate = null;



      this.method = "next";

      this.arg = undefined;



      this.tryEntries.forEach(resetTryEntry);



      if (!skipTempReset) {

        for (var name in this) {

          // Not sure about the optimal order of these conditions:

          if (name.charAt(0) === "t" &&

              hasOwn.call(this, name) &&

              !isNaN(+name.slice(1))) {

            this[name] = undefined;

          }

        }

      }

    },



    stop: function() {

      this.done = true;



      var rootEntry = this.tryEntries[0];

      var rootRecord = rootEntry.completion;

      if (rootRecord.type === "throw") {

        throw rootRecord.arg;

      }



      return this.rval;

    },



    dispatchException: function(exception) {

      if (this.done) {

        throw exception;

      }



      var context = this;

      function handle(loc, caught) {

        record.type = "throw";

        record.arg = exception;

        context.next = loc;



        if (caught) {

          // If the dispatched exception was caught by a catch block,

          // then let that catch block handle the exception normally.

          context.method = "next";

          context.arg = undefined;

        }



        return !! caught;

      }



      for (var i = this.tryEntries.length - 1; i >= 0; --i) {

        var entry = this.tryEntries[i];

        var record = entry.completion;



        if (entry.tryLoc === "root") {

          // Exception thrown outside of any try block that could handle

          // it, so set the completion value of the entire function to

          // throw the exception.

          return handle("end");

        }



        if (entry.tryLoc <= this.prev) {

          var hasCatch = hasOwn.call(entry, "catchLoc");

          var hasFinally = hasOwn.call(entry, "finallyLoc");



          if (hasCatch && hasFinally) {

            if (this.prev < entry.catchLoc) {

              return handle(entry.catchLoc, true);

            } else if (this.prev < entry.finallyLoc) {

              return handle(entry.finallyLoc);

            }



          } else if (hasCatch) {

            if (this.prev < entry.catchLoc) {

              return handle(entry.catchLoc, true);

            }



          } else if (hasFinally) {

            if (this.prev < entry.finallyLoc) {

              return handle(entry.finallyLoc);

            }



          } else {

            throw new Error("try statement without catch or finally");

          }

        }

      }

    },



    abrupt: function(type, arg) {

      for (var i = this.tryEntries.length - 1; i >= 0; --i) {

        var entry = this.tryEntries[i];

        if (entry.tryLoc <= this.prev &&

            hasOwn.call(entry, "finallyLoc") &&

            this.prev < entry.finallyLoc) {

          var finallyEntry = entry;

          break;

        }

      }



      if (finallyEntry &&

          (type === "break" ||

           type === "continue") &&

          finallyEntry.tryLoc <= arg &&

          arg <= finallyEntry.finallyLoc) {

        // Ignore the finally entry if control is not jumping to a

        // location outside the try/catch block.

        finallyEntry = null;

      }



      var record = finallyEntry ? finallyEntry.completion : {};

      record.type = type;

      record.arg = arg;



      if (finallyEntry) {

        this.method = "next";

        this.next = finallyEntry.finallyLoc;

        return ContinueSentinel;

      }



      return this.complete(record);

    },



    complete: function(record, afterLoc) {

      if (record.type === "throw") {

        throw record.arg;

      }



      if (record.type === "break" ||

          record.type === "continue") {

        this.next = record.arg;

      } else if (record.type === "return") {

        this.rval = this.arg = record.arg;

        this.method = "return";

        this.next = "end";

      } else if (record.type === "normal" && afterLoc) {

        this.next = afterLoc;

      }



      return ContinueSentinel;

    },



    finish: function(finallyLoc) {

      for (var i = this.tryEntries.length - 1; i >= 0; --i) {

        var entry = this.tryEntries[i];

        if (entry.finallyLoc === finallyLoc) {

          this.complete(entry.completion, entry.afterLoc);

          resetTryEntry(entry);

          return ContinueSentinel;

        }

      }

    },



    "catch": function(tryLoc) {

      for (var i = this.tryEntries.length - 1; i >= 0; --i) {

        var entry = this.tryEntries[i];

        if (entry.tryLoc === tryLoc) {

          var record = entry.completion;

          if (record.type === "throw") {

            var thrown = record.arg;

            resetTryEntry(entry);

          }

          return thrown;

        }

      }



      // The context.catch method must only be called with a location

      // argument that corresponds to a known catch block.

      throw new Error("illegal catch attempt");

    },



    delegateYield: function(iterable, resultName, nextLoc) {

      this.delegate = {

        iterator: values(iterable),

        resultName: resultName,

        nextLoc: nextLoc

      };



      if (this.method === "next") {

        // Deliberately forget the last sent value so that we don't

        // accidentally pass it on to the delegate.

        this.arg = undefined;

      }



      return ContinueSentinel;

    }

  };



  // Regardless of whether this script is executing as a CommonJS module

  // or not, return the runtime object so that we can declare the variable

  // regeneratorRuntime in the outer scope, which allows this module to be

  // injected easily by `bin/regenerator --include-runtime script.js`.

  return exports;



}(

  // If this script is executing as a CommonJS module, use module.exports

  // as the regeneratorRuntime namespace. Otherwise create a new empty

  // object. Either way, the resulting object will be used to initialize

  // the regeneratorRuntime variable at the top of this file.

  typeof module === "object" ? module.exports : {}

));